Transnasal method and catheter for lacrimal system

ABSTRACT

A balloon catheter for treatment of a patient&#39;s lacrimal system is applied transnasally without the use of a guide wire or a curve retention member. The catheter is formed of a stainless steel hypotube and is of sufficient stiffness and column strength to enable the deflated catheter to be pushed from the patient&#39;s nasal cavity through a prepared small-tight opening, which is formed through the lateral nasal wall and lacrimal fossa, into the lacrimal sac. The catheter has a proximal shaft and a distal segment positioned by a bend at an angle of 70° to 115°, preferably 90°, to the proximal shaft. An inflatable member is mounted about the distal segment and is adhesively bonded to the distal end of the proximal shaft, the bend, and the proximal end of the distal segment and to the distal portion of the distal segment. The prepared, small-tight opening is formed by pushing small holes through the medial sac, lacrimal fossa, and lateral nasal wall with an instrument and coalescing the holes to form the prepared small-tight opening. The catheter is introduced into the nasal cavity and rotated, or moved, to align the distal segment with the prepared opening. The distal segment is then pushed through the prepared opening, and fluid under pressure is applied to the catheter to inflate the inflatable member and dilate the prepared opening.

PRIOR APPLICATION

This is a divisional of U.S. patent application Ser. No. 10/259,630,filed Sep. 30, 2002, now U.S. Pat. No. 7,169,163 issued Jan. 30, 2007.

FIELD OF THE INVENTION

This invention relates to a method and catheter for treating thelacrimal system and, more particularly, to a transnasal method oftreating the lacrimal system and a balloon catheter used in this method.

BACKGROUND

To fully understand the invention, it is necessary to consider theanatomy and physiology of the lacrimal system. The orbital portion ofthe lacrimal gland is located in the superotemporal orbit and producesthe aqueous layer of the tear film. Ductules from the orbital portion ofthe lacrimal gland pass through the adjacent palpebral lacrimal gland toempty in the superior conjunctival cul-de-sac. Smaller accessorylacrimal glands in the upper and lower lids also contribute to tearproduction The tears bathe the surface of the eye and then drain intothe puncta and canaliculi in the medial upper and lower lids. The tearsflow from the canaliculi into the lacrimal sac down the nasolacrimalduct into the nose.

The nasolacrimal duct can become obstructed on either a congenital oracquired basis When the nasolacrimal duct becomes obstructed, tears canno longer drain from the surface of the eye through the lacrimal systeminto the nose. The tears well up over the eye and spill over the lidsonto the face. The patient has to constantly dab the eye with a tissue.In addition, tears stagnate in the lacrimal sac, bacteria multiply, andin many cases the lacrimal sac becomes infected (dacryocystitis).Dacryocystitis causes the lacrimal sac to become swollen, red andpainful. Pus exudes from the sac and constantly covers the eye. In time,the dacryocystitis does not respond to antibiotics and surgery becomesnecessary. At present, there is no medical therapy for acquirednasolacrimal duct obstruction other than antibiotics to temporarilysuppress infection.

The condition can, however, be corrected surgically.Dacryocystorhinostomy (DCR) is the surgery required to correctnasolacrimal duct obstruction. In a DCR, a new opening (ostium) iscreated between the lacrimal sac and the nose. This allows tears to flowfrom the lacrimal sac through the DCR ostium into the nose. An externalor incisional DCR required an incision on the side of the nose. In anopen DCR, the surgeon creates a large 17 mm plus diameter opening in thebone and nasal muscosa. This procedure has significant morbidity, aprolonged recovery, and the threat of scarring and hemorrhage. Incontrast, an endoscopic DCR has much less morbidity, no incision, and aquick recovery time. An endoscopic DCR may be performed using a ballooncatheter, a laser, or traditional surgical instruments. A laserendoscopic DCR requires expensive and time-consuming lasers, and has alow success rate. An endoscopic DCR with traditional instruments placesthe eye and surrounding structures at risk because tissue is removedfrom the lacrimal sac and lateral nasal wall, with the instruments inthe nasal cavity going toward the eye and orbit. Bleeding and edema maymake it difficult to identify the relevant structures.

It has been found that a balloon catheter DCR is a much safer andcheaper form of DCR than a laser or an endoscopic DCR with traditionalsurgical instruments. The balloon catheter is positioned so that itextends from the lacrimal sac through the ostium and extends into thenose. Since the balloon DCR ostium is created by dilatation, rather thanby excision or laser energy, there is no threat to the surroundingocular and orbital structures, and there is less tissue trauma.

As shown in U.S. Pat. Nos. 5,021,043 and 5,169,043, I have previouslyco-invented balloon catheters for use in the lacrimal system. Theseballoon catheters are inserted from the eye through the small diameter(about 0.5 mm) delicate punctum and canaliculus into the lacrimal sacextending through the planned ostium into the nose. The deflated profilediameter of the balloon catheter must be very small in order to bepushed through, and avoid damage to, the small diameter and delicatecanaliculus. The need for such a small deflated diameter limits theinflated diameter of the balloon to 5 mm. However, a 5 mm diameterostium is much smaller than the 17 mm plus diameter ostium of anexternal DCR and leads to a higher stenosis rate of the balloon DCRostium after surgery. A larger diameter balloon would create alarger-diameter ostium and lead to a higher surgical success rate.

This led to the concept disclosed beginning at column 7, line 29, andFIG. 4 of the U.S. Pat. No. 5,021,043 patent and beginning at column 8,line 34, and FIG. 4 of the U.S. Pat. No. 5,169,386 patent that adilation catheter be introduced transnasally when a larger-diameterballoon is required. However, as taught in these patents, the dilationcatheter is inserted over a guide wire. Although this technique isuseful, it involves a number of time-consuming steps, including theinsertion of a guide wire through the lacrimal system, and thenseparately advancing the balloon catheter over the guide wire. Thistechnique requires the placement of a guide wire through the canaliculiinto the nose. The surgeon then reaches up the nose with a hemostat orother instrument to grasp the guide wire and pull it out of the externalnaris of the nose. A flexible balloon catheter is then passed up thenose over the guide wire and through the lateral nasal wall into thelacrimal sac, or up the nasolacrimal duct into the lacrimal sac.However, there are problems with this method. First, there may bedifficulty locating and grasping the guide wire in the nose, especiallyif even mild bleeding is present. The guide wire may pass posteriorlyinto the throat (pharynx) rather than in the direction of the externalnaris. There is often resistance to pulling the balloon from the nasalcavity into the lacrimal sac and considerable force is required to pullthe balloon and guide wire into the lacrimal sac. This pull on the guidewire can cause it to slice through the delicate canaliculi, which maylead to secondary fibrosis and obstruction of the canaliculi aftersurgery.

The U.S. Pat. No. 5,169,386 patent also discloses an alternativedilation catheter, which does not use a guide wire, but there is nosuggestion that this catheter be inserted transnasally. The catheter isconstructed to simulate a standard ophthalmic probe in stiffness, interms of both column strength and resistance to lateral bending, withsufficient flexibility to enable it to conform to the contours of thelacrimal system. The catheter, as provided, is initially straight, butthe catheter may be bent between 0°-30° to simulate the curvature of anophthalmic probe. A curve retention element is inserted in the catheterto retain the curved shape and to increase the columnar and flexuralstiffness of the distal portion of the catheter to enhance its abilityto be forced through a constricted portion of the lacrimal system. Thecatheter is formed of a stainless steel hypotube having an outerdiameter of 0.022″ and an inner diameter of 0.017″.

This catheter is not suitable for transnasal insertion. The tube doesnot have sufficient stiffness and column strength to enable the deflatedballoon catheter to be pushed from the nasal cavity through a small,tight opening in the lateral nasal wall and lacrimal fossa into thelacrimal sac. Moreover, the bent distal portion is not angled to adegree necessary for ready insertion through the opening.

SUMMARY

A balloon catheter of the invention can be introduced transnasally intothe area of a planned DCR ostium. The catheter has a larger deflatedprofile and, thus, a larger inflated diameter, than a balloon catheterintroduced through the delicate canaliculi. The balloon catheter of theinvention does not need a guide wire; and, therefore, there is no chancethat a guide wire will damage the delicate canaliculi. A larger diameterballoon DCR ostium is less likely to stenose after surgery and resultsin a better surgical success rate.

The balloon catheter of the invention comprises a hypotube formed ofstainless steel of sufficient stiffness and column strength to enablethe deflated balloon catheter to be pushed from the nasal cavity througha prepared small, tight opening in the lateral nasal wall and lacrimalfossa into the lacrimal sac. A distal end segment of the hypotube has arounded bend, placing the distal segment at an angle of 70° to 115°,preferably 90°, to a long proximal segment or shaft. This bend allowsthe surgeon to rotate or shift the position of the long proximalcatheter shaft, thus placing the distal balloon catheter segment inposition to enter from the nasal cavity into the lacrimal sac at variousangles appropriate to each individual patient. Due to the stiffness andstrength of the hypotube, neither a guide wire nor a curve retentionelement are necessary.

The distal segment of the balloon catheter from the outside of the bendto the end of the catheter is 14 mm which is short enough to allow it tobe rotated within the nasal cavity and long enough to allow a balloon ofsufficient length and diameter to be attached to the hypotube fordilatation of the balloon DCR ostium.

The balloon is formed of inflatable material with a first neck bondedwith adhesive to the very distal portion of the distal segment of thehypotube and a second neck bonded with adhesive to the distal end of theproximal shaft, the bend, and the proximal end of the distal segment.This permits a longer working segment of balloon to be used, because thearea of adhesion of the balloon includes the bend and the adjacentportion of the proximal long segment of the hypotube. The proximal endof the catheter tube has a luer lock with wings or an expansion to allowthe catheter to be attached to tubing from the inflation device. Thewings or expansion allow the surgeon to more easily hold, manipulate,and push the balloon catheter.

According to the method of the invention, a very large ostium is formedbetween the lacrimal sac and the nasal cavity with the use of a verylarge balloon inserted transnasally. The balloon is deflated to allowthe catheter, which is of sufficient stiffness, to be pushed through theprepared opening formed from the nasal cavity through the lateral nasalwall and lacrimal fossa into the lacrimal sac The balloon is theninflated to enlarge the opening and create the very large ostium. Theballoon catheter is inserted without the use of a guide wire.

The portion of the distal end after the bend is sufficiently short toenable the catheter to be positioned in the nasal cavity to bring thedistal end to the level of the prepared opening. The catheter is thenrotated or shifted to align the distal end with the prepared opening, asrequired by the anatomy of the individual patient. The distal end isthen pushed through the prepared opening to position the deflatedballoon in the opening. The balloon is then inflated to enlarge theopening to the outer diameter of the inflated balloon, thus forming thevery large ostium.

Since the method of the insertion requires insertion of the ballooncatheter transnasally, the trauma associated with insertion through thedelicate canaliculi is avoided. The catheter and method of the inventionprovide a satisfactory endoscopic DCR and thus avoid the traumaassociated with an external (incisional) DCR. The catheter and method ofthe invention achieve a high surgical success rate.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic drawing of a preferred embodiment of a lacrimalballoon catheter of the invention;

FIG. 1 a is a close-up schematic drawing of the tip of the distalsegment of the balloon catheter of FIG. 1;

FIG. 2 is a schematic drawing of a step of the method of the inventionshowing a patient with an obstructed nasolacrimal duct in which a metalprobe has been passed through the punctum, canaliculus, lacrimal sac,and multiple spots in the lacrimal fossa and lateral nasal wall into thenose;

FIG. 3 is a schematic drawing showing another step of the method of theinvention in which a nerve hook brought up the nasal cavity, pushed intothe small openings in the lateral nasal wall and lacrimal fossa, andmoved to coalesce these small openings into a larger opening;

FIG. 4 is a schematic drawing showing a further step of the method ofthe invention in which a deflated balloon catheter of the invention,which has been brought into the nasal cavity and pushed through thesmall opening in the lateral nasal wall and lacrimal fossa into thelacrimal sac;

FIG. 5 is a schematic drawing showing a step of the method of theinvention in which the balloon catheter with the balloon inflated iswithin the ostium and lacrimal sac; and

FIG. 6 is a close-up schematic drawing of the tip of the distal portionof an alternative embodiment of a balloon catheter of the invention; and

FIG. 7 is a schematic diagram showing a method step of an alternativeembodiment of the method of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

As shown in FIGS. 1 and 1 a, a balloon catheter 130 of the invention isassembled from a tube 136, preferably a stainless steel hard temperedhypotube which has a circular bend 138 of 0.13″ radius such that distalsegment 137 is oriented 70° to 115°, preferably 90°, to proximal segment139. The distance from the distal tip 184 of distal segment 137 to theouter wall of proximal segment 139 of hypotube 136 is 4 mm to 30 mm,preferably 14 mm, as shown in FIG. 1. The distal tip 184 of the hypotube136 is closed, whereas the proximal end 142 is open. However, the lumenof tube 136 may be closed in the distal segment 137, up to 10 mm fromthe distal tip 184 allowing the distal tip 184 to remain open forengagement with a probe, as shown in FIGS. 6 and 7. The proximal end 142of hypotube 136 is inserted into a mold for forming luer 144. Heatedplastic is injected into the mold to form luer 144 attached to proximalend 142. The inner diameter of the luer 144 matches the externaldiameter of the hypotube 136. The luer 144 has wings 143 or otherenlargement or expansion on it to enable the surgeon to better hold andmanipulate the balloon catheter 130. Catheter 130 is 4″ to 10″ long,preferable 6″ in length as measured from proximal end 142 to distal tip184, as shown in FIG. 1. The wall of tube 136 should be of suchthickness that the tube has sufficient stiffness and column strengththat distal segment 137 of a deflated catheter can be pushed through aprepared small, tight opening in the patient's lateral nasal wall. Thismay require considerable pressure in some cases. It has been found thata tube with a wall thickness of at least 0.035″ will be satisfactory. Apreferred tube has an outer diameter of 0.083″ and an inner diameter of0.039″ with a wall thickness of 0.044″.

The catheter 130 has a port 140 in the distal segment 137, which isformed by inserting temporarily a discardable wire segment into the tube136. This is done before inserting hypotube 136 into luer 144. Atransverse slot is cut in the tube 136 approximately 2 mm to 14 mm,preferably 4 mm, from its distal end 184 to form port 40. The slotextends in depth to approximately one third of the diameter of tube 136.A wire wheel is used to remove any burrs, and the discardable core wireis removed and discarded.

Catheter 130 has sufficient column strength and resistance to lateralbending (stiffness) to enable the deflated catheter to be pushed throughthe initial prepared opening in the lateral nasal wall and lacrimalfossa into the lacrimal sac. This may require considerable pressure insome cases.

A balloon 134 is preferably formed of polyethylene terephthalate and hasa length of approximately 4 mm to 30 mm, preferably 14 mm, and a workinginflated diameter of 2 mm to 14 mm, preferably 9 mm, for use in thelacrimal system. The balloon has a distal neck 170, a distal taperedregion 172, a center region 174, a proximal tapered region 176, and aproximal neck 178. During installation, tube 136 is cleaned withisopropanol and then coated with a primer, “Loctite 770.” The balloon isplaced over the distal end of tube 136 to align the distal end of distalneck 170 with distal end 184 of tube 136. An adhesive, such ascyanoacrylate, is used. An acceptable adhesive “Loctite 4081” isavailable from Loctite Corporation. The adhesive is applied to distalend of distal neck 170 and the proximal end of proximal neck 178 to formbonds 180 and 182, respectively. The adhesive is applied to the balloonnecks 170, 178 using a small mandrel such as a wire approximately 0.010″to 0.014″ in diameter. The adhesive wicks into the necks due tocapillary action. Proximal neck 178 and proximal tapered region 176 maybe bonded on distal segment 137 of tube 136 or extend over bend 138 ontothe distal end portion of proximal segment 139 of tube 136. Extension ofthe proximal neck 178 onto bend 138 and proximal segment 139 allows agreater length of the working diameter, i.e., center region 174, to beon distal segment 137 of tube 136.

A first step of the method of the invention is shown in FIG. 2. A Bowmanprobe 102 is brought through superior punctum 4 of the patient's eye,superior canaliculus 6, common canaliculus 8, and lacrimal sac 10, andthen pushed through the medial sac wall 11, lacrimal fossa bone 12, andlateral nasal wall 44 into the nasal cavity 38. Probe 102 is pulled backinto lacrimal sac 10, and pushed through four or fives areas of medialsac wall 11, lacrimal fossa bone 12, and lateral nasal wall 44 intonasal cavity 38. The multiple openings 18 in the medial sac wall 11,lacrimal fossa 12, and lateral nasal wall 44 are coalesced into oneprepared opening 19 (FIG. 4) by moving probe 102 in a see-saw fashion orby bringing a nerve hook 104 into nasal cavity 38, and pushing it intoopenings 18 and dragging nerve hook 104 across multiple openings, asshown in FIG. 3.

Turning to FIG. 4, the deflated transnasal lacrimal balloon catheter 130is then brought into nasal cavity 38, and distal segment 137 is pushedthrough prepared opening 19 created by coalescing smaller openings 18 inlateral nasal wall 44, lacrimal fossa 12, and medial wall 11 of lacrimalsac 10, such that distal end 184 of distal segment 137 of ballooncatheter 130 extends into lacrimal sac 10.

The luer lock 144 on proximal end 142 of balloon catheter 130 connectsto the distal end 110 of tube 112 of the inflation device, whichsupplies fluid under pressure. As seen in FIG. 5, balloon 134 isinflated to 9 bars for 20 seconds to expand opening 19 to form ostium120 then deflated. Distal segment 137 is then slightly repositioned toinsure thorough dilation and inflated again to 9 bars for 20 seconds.Balloon 134 is then deflated and withdrawn from nasal cavity 38, leavinga large ostium 120 formed between lacrimal sac 10 and nasal cavity 38.

An alternative embodiment of the balloon catheter of the invention isshown in FIG. 6. In this embodiment, the catheter 230 has a distalsegment 237, which are identical to catheter 130 and segment 137, asshown in FIG. 1, except for the point of closure of tube 136. Whereas,as described above, distal segment 137 in FIG. 1 is closed at its distalend 184, in the embodiment of FIG. 6, tube 236, and distal segment 237are closed by closure wall 286 that is located between slot 140 and thedistal end 284. Since distal segment 237 is closed after slot 140, fluidwill still flow through slot 140 to inflate balloon 134 when air underpressure is applied to tube 236. However, there will now be anopen-ended tube segment 288 between closure wall 286 and distal end 284.

As shown in FIG. 7, this open-ended tube segment 288 may be used toreceive an end of a probe 202, provided that the outer diameter of probe202 is slightly smaller than the inner diameter of tube segment 288.Such a probe engaged with open-ended tube segment 288 can be useful formoving distal end 284 to a proper position for engagement with anopening 19 which is to be enlarged by inflating balloon 134, asdescribed above.

It should be understood that the foregoing description of the inventionis intended merely to be illustrative and other modifications,embodiments, and equivalents may be apparent to those skilled in the artwithout departing from the spirit and scope of the invention.

1. A device for dilating an opening between a patient's lacrimal sac andnasal cavity to treat the: lacrimal system, comprising: a tubular body,said tubular body having a proximal end, a proximal segment, a distalend, a distal segment, said distal segment having a fixed angle relativeto said proximal segment, and said tubular body having sufficientcompressive strength to resist buckling and sufficient lateral stiffnessto retain said angle when correctly utilized during treatment; a luer,said luer fixedly attached to said proximal end; an inflatable member,said inflatable member being proximate to said distal segment, saidinflatable member, when inflated, having a center region sufficientlydimensioned to dilate said opening.
 2. The device of claim 1, whereinsaid body further has a rounded bend between said proximal segment andsaid distal segment.
 3. The device of claim 2, wherein inflatable membercomprises a working segment located entirely distal to said bend.
 4. Thedevice of claim 1, wherein said tubular body is a stainless steelhypotube having a wall thickness of at least 0.035″.
 5. The device ofclaim 1, wherein said tubular body is a stainless steel hypotube havingan outer diameter of 0.083″ and an inner diameter of 0.039″ with a wallthickness of 0.044″.
 6. The device of claim 1, wherein said angle isfrom 70° to 115°.
 7. The device of claim 1, wherein said luer has ameans for improving a user's manipulating of said device duringtreatment.
 8. The device of claim 1, wherein said inflatable member hasa length of 4 millimeters to 30 millimeters.
 9. The device of claim 1,wherein said inflatable member has an inflated diameter of 2 millimetersto 14 millimeters.